KEM0031 Sigma-Aldrich

Klenow Fragment

Ultra-pure enzyme for nucleic acid modifications



grade   for molecular biology
assay   >99% (SDS-PAGE)
form   buffered aqueous solution
specific activity   5,000 U/mg
concentration   5,000 U/mL
shipped in   dry ice
storage temp.   −20°C


General description

Klenow Fragment is a mesophilic DNA polymerase derived from the E.coli Polymerase I DNA-dependent repair enzyme. The enzyme exhibits DNA synthesis and proofreading (3′ → 5′) nuclease activities, and, in the absence of the holoenzyme’s (5′→3′) nuclease domain, displays a moderate strand displacement activity during DNA synthesis. The protein is expressed as a truncated product of the E.coli PolA gene.


Suitable for:
• DNA blunting by fill-in of 5’ overhang
• Second strand cDNA synthesis
• Sequencing
• Site-specific mutagenesis

Features and Benefits

• Ultra-purification process for ultimate enzyme performance
• Highest quality specifications for ultimate product consistency
• Undetectable DNA and nuclease contamination


Supplied with:KEM0042B (10X Blue Buffer)

Unit Definition

1 unit is defined as the amount of polymerase required to convert 10 nmol of dNTPs into acid insoluble material in 30 minutes at 37° C.

Physical form

Supplied in 100 mM KPO4, 1.0 mM DTT, 0.1 mM EDTA, and 50% glycerol at pH 7.4 @ 25° C.

Other Notes

Source of protein: A recombinant E. coli strain carrying the Klenow Fragment gene.

Unit size: 2,500 U

Safety & Documentation

Safety Information

NONH for all modes of transport


Certificate of Analysis (COA)

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Protocols & Articles


Nucleic Acid Modifying Enzyme Selection Chart (Ultra Pure)

DNA Polymerases synthesize DNA from nucleotides.  DNA polymerase is required for DNA replication, but also essential for many other activities in the cell, including genetic recombination, DNA repair...
Keywords: Amplification, Cloning, DNA replication, Genetic, Molecular biology, Peptide synthesis, Polymerase chain reaction, Purification, Recombination, Sequencing, Transcription, Whole genome amplification


Cloning Protocol for the Gene-of-Interest into a Plasmid Vector

Genetic engineering is used in thousands of laboratories around the world. Given its importance it is remarkable that cloning strategies for many of the popular DNA components are not standardised. C...
Keywords: Antibiotics, Buffers, Cloning, Degradations, Dialysis, Digestions, Gene expression, Genetic, Genetics, Individual protein Immunoprecipitation, Molecular biology, Nucleic acid annealing, Peptide synthesis, Phosphorylations, Polymerase chain reaction, Precipitation, Purification, Sequencing, Substitutions, transformation

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Keywords: Cell culture, Cloning, Gene expression, Genetic, Genetics, Metabolic Pathways, Metabolites, Molecular biology, Molecular biology techniques, Photosynthesis, Poisons, Polymerase chain reaction - quantitative, Transcription, Transfection

Peer-Reviewed Papers


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